Jacob, Joseph's father, adopted Joseph's two sons, Manasseh and Ephraim, to share in Jacob's inheritance equally with Jacob's own sons. (Genesis 48:5) He is counted as the founder of the IsraeliteTribe of Manasseh, one of the twelve Israelite tribes. Jacob also blessed Ephraim over his older brother. (Genesis 48:20) "Manasseh" in Hebrew means "forgetful."

Some biblical scholars view this as postdiction, an eponymousmetaphor providing an aetiology of the connectedness of the tribe to others in the Israelite confederation.[1] The text of the Torah argues that the name of Manasseh is etymologically derived from the root נשה nasah, which means to forget, and goes on to argue that it refers to Joseph forgetting his troubles and his father's household, on account of the actions of God.[2] Other scholars maintain that the name is of Egyptian rather than Hebrew origin.[3]

In the Biblical account, Joseph's other son is Ephraim, and Joseph himself is one of the two children of Rachel and Jacob, the other being Benjamin. Biblical scholars regard it as obvious, from their geographic overlap and their treatment in older passages, that originally Manasseh and Ephraim were considered one tribe - that of Joseph;[4] according to several biblical scholars, Benjamin was also originally part of this single tribe, but the biblical account of Joseph as his father became lost.[4][5] A number of biblical scholars suspect that the distinction of the Joseph tribes (including Benjamin) is that they were the only Israelites which went to Egyptand returned, while the main Israelite tribes simply emerged as a subculture from the Canaanites and had remained in Canaan throughout.[5][6] According to this view, the story of Jacob's visit to Laban to obtain a wife originated as a metaphor for this migration, with the property and family which were gained from Laban representing the gains of the Joseph tribes by the time they returned from Egypt;[5] according to textual scholars, the Jahwist version of the Laban narrative only mentions the Joseph tribes, and Rachel, and doesn't mention the other tribal matriarchs whatsoever.[7][8]

In the Torah, the eventual precedence of the tribe of Ephraim is argued to derive from Joseph tricking Jacob, blind and on his deathbed, into blessing Ephraim before Manessah.[9][10] The text describing this blessing features a hapax legomenon - the word שכל (sh-k-l) - which classical rabbinical literature has interpreted in esoteric manners;[11] some rabbinical sources connect the term with sekel, meaning mind/wisdom, and view it as indicating that Jacob was entirely aware of who he was actually blessing;[12] other rabbinical sources connect the term with shikkel, viewing it as signifying that Jacob was despoiling Manasseh in favour of Ephraim;[13] yet other rabbinical sources argue that it refers to the power of Jacob to instruct and guide the holy spirit.[14]